In the current communication technology, more and more emphases are put on the reliability and fault processing ability of the communication network; that is, it needs to find the fault quickly and also to perform protection switching of the service quickly, i.e. the master state can be switched to the standby state quickly after a fault is found so as to achieve normal implementation of the service. The Internet Protocol (IP) network, especially the telecommunication-level Ethernet that is popular in recent years, puts the protection switching ability of the network in the first place. The current bearer network adopts various technologies to improve the speed of checking network fault and protection switching performance, thereby reducing the influence of network fault on services, and hence decreasing service unavailable probability and improving the service reliability. The following technologies are usually used at the Provider Edge (PE) side: Traffic Engine Fast ReRoute (TE FRR), Virtual Private Network (VPN FRR), Operation, Administration, Maintenance (OAM), Bidirectional Forwarding Detection (BFD), etc. The above technologies improve the speed of checking network fault and protection switching performance in the corresponding application scenarios. It is ensured by establishing master and standby links or master and standby Pseudo Wires or even master and standby tunnels that the traffic can be switched to the standby one quickly when the mater link, master Pseudo Wire or master tunnel has a fault, thereby guaranteeing the reliability of communication.
Access policies such as redundancy backup or load sharing are usually adopted in the CE access layer, or Rapid Spanning Tree Protocol (RSTP), VRRP or other means is used to achieve protection switching, but VRRP is a level 3 redundancy backup protocol. The VPLS technology in level 2 VPN (L2VPN) is a technology commonly used in the bearer network, and the protection switching ways usually used in VPLS are VPN FRR, TE FRR and so on, and these protection ways are all intended to protect the network of the provider.
In specific implementation process, the inventor of the present invention finds that in the VPLS environment, the AC access of the CE side cannot sense the state of VC, and when the VC state of the network operator changes, it cannot inform the AC access side in time and enable the AC access side to switch, thereby causing slowness or even interruption of service switching.